Electronic acoustical stringed instrument



P 1960 H. B. NEWTON 2,953,052

ELECTRONIC ACOUSTICAL STRINGED INSTRUMENT Filed Feb. 24, 1959 11110'IIIIII.

69mm 5 Mwnw IN VEN TOR.

United States Patent Office r 2,953,052 Patented Sept. 20, 1960ELECTRONIC ACOUSTICAL STRINGED INSTRUMENT Harold B. Newton, 44859 FoxtonAve., Lancaster, Calif. Filed Feb. 24, 1959, Ser. No. 794,950

4 Claims. (Cl. 84-1.16)

The invention relates to stringed instruments which are adapted to beplayed in the normal fashion and which are additionally provided with anamplification system connected to a pick-up and loudspeaker so that thesound produced by the instrument can also be heard through theloudspeaker equipment. The invention has special reference to thoseinstruments which embody a case with an opening therein over whichstrings are stretched in a manner such that the strings can be pluckedto produce musical tones with the aid of the case which acts as asounding box. Those instruments wherein the invention is especiallyadvantageous are instruments of the nature of guitars, mandolins, theviolin class of instruments, zithers, etc.

In instruments of the type made reference to where electronic equipmenthas heretofore been installed, certain objections have been found to thecharacter of the music which reaches the car through the amplificationsystem. The objectionable characteristics are implemented by use of someform of pick which is used customarily to set the strings in vibration.Pick tone or pick slap, as this effect is frequently termed, comprisesharsh sounds usually of high frequency which are irritating oruncomfortable when reaching the ear through the amplification systembecause the prominence of the objectionable sounds is emphasized in thesystem. In those electronic pick-ups heretofore employed, the microphoneemployed is one usually set in the case or sound box near the strings insuch fashion that it picks up all of the sounds created when the stringsare struck and though capable of being regulated with respect to volume,is incapable of filtering out the objectionable pick slap sounds.Although such filtering can and has been accomplished in the electricsystem, this type of regulation is not popular because of its complexityand the need for frequent adjustment.

It is, therefore, among the objects of the invention to provide a newand improved electronic acoustical stringed instrument which is of suchconstruction that pick tones and related objectionable tones createdwhen the strings are struck are filtered out so that they never reachthe electronic pick-up and hence cannot be amplified in theamplification system.

Another object of the invention is to provide a new and improvedelectronic acoustical stringed instrument which is equipped withfiltering media for directly filtering out objectionable pick tonesbefore they reach the electronic pick-up, but which is: also capable ofemitting sounds normally expected of the instrument when'played withoutemployment of the electronic amplification system.

Still another object of the invention is to provide a new and improvedelectronic acoustical stringed instrument which may be provided with oneor more 2 pick-up, solely as a purely acoustical instrument or with bothsources of tone production in operation simultaneously.

Still another object of the invention is to provide a and improvedelectronic acoustical stringed instrument provided with filters forfiltering out pick tones and related tones within the sound box or caseof the instrument, the filtering system being of such character that itis entirely concealed within the instrument and which, moreover, doesnot interfere in any manner, whatsoever, with the normal acousticalproperties of the instrument, the filtering system moreover being ofsuch a design and construction that it can be built into conventionalinstruments without alteration of design of the instrument.

With these and other objects in view, the invention consists of theconstruction, arrangement and combination of the various parts of thedevice whereby the objects contemplated are attained, as hereinafter setforth, pointed out in the appended claims, and illustrated in theaccompanying drawings.

Figure 1 is a plan view of a typical stringed inst-rument such as aguitar equipped with the invention.

Figure 2 is a fragmentary longitudinal sectional view taken on the line22 of Figure 1.

Figure 3 is a fragmentary cross-sectional view of a shutter controltaken on the line 3--3 of Figure 1.

Figure 4 is a fragmentary plan view of a hinge element for one of theshutters.

Figure 5 is a fragmentary sectional view taken on the line 55 of Figure4.

Figure 6 is a fragmentary cross-sectional view taken on the line 6-6 ofFigure '1.

In an embodiment of the invention chosen for the purpose ofillustration, a guitar type instrument is shown consisting of a case orsound box 10, a neck 11, a bridge 12, and a string mounting manifold '13arranged in customary fashion whereby to support a set of six strings 9.

The case comprises a lower wall 14, an upper wall 15 and a side wall 16extending entirely around the perimeter so as to enclose a chamber orresonant space 17.

In the particular instrument shown for purposes of illustration, anelectronic sound pick-up 18 is located near the end of the case 10 whichis remote from the neck 11. The precise location of a microphone end 19of the pick-up 18 is not of material consequence except that itpreferably lies within a portion of the chamber 17 somewhat removed fromthe origin of sounds and tones which will ultimately be picked up. Thesound pick-up is of substantially conventional construction such as iscommonly available for this purpose, and is provided with a conventionalvolume control 20 on the upper wall of the case at a convenientlocation, a jack or instrument plug 21 of the usual sort and a switch 22for turning the electrical system off and on.

Extending through the upper wall 15 in the chosen embodiment are twoinlet openings 23 and 24. These openings lie immediately below thestrings 9 so as to receive sounds produced by the strings when they arestruck. Two inlet openings are shown only by way of illustrationinasmuch as in a guitar type instrument the multiple type openings areuseful, namely the opening 23 for emphasizing the treble tones and theother, opening 24, for emphasizing the bass tones.

Beneath the inlet opening 23, for example, is a box 25 which is closedon all four vertical sides and which is open at the top beneath theinlet opening 23. The box 25 has also a bottom 26 which closes the boxon the lower side except for an outlet hole 27 which communicates with atube 28. The tube may be of any convenient cross-sectional shape which,in one chosen example, is round and molded integrally with the box 25.The tube 28 extends obliquely downwardly and forward- 1y from the box ina direction generally toward the end of the chamber 17 remote from thepick-up 13. An outlet opening 29 opens into the chamber 17 at the end ofthe tube. Within the tube are located filters 3t), 31 and 32. These maybe mounted by any convenient means so that they remain fixed in positiononce assembled. The filters may be constructed of various materials suchas cloth or porous cellulose material, or may be merely in the nature ofbafiles. They should, in any event be constructed in such fashion and somounted that they do not obstruct the passage of sound through the tube,but merely filter out objectionable sounds which usually occur at highfrequencies.

Mounted at the upper end of the box 25 is a shutter 33 large enough inarea so as to completely cover the inlet opening 23. Hinges 34 have oneend 35 of each attached to the shutter 33 and the other end 36 attached,preferably to the underside of the upper wall 15. A hinge pin 37 isfastened to the end 35 by some adequate conventional means providing notonly a pivot between the ends 35 and 36, but also an agency for rotatingthe shutter 33 between the closed position illustrated by the solidlines in Figure 2, and open position illustrated by the broken lines.For convenience, the hinge pin is flexible in character and containedwithin a sheathing 38 attached to a fixture 39, the fixture in turnbeing secured to the underside of the upper wall 15. A button 40attached to the pin 37 on the outside face of the upper wall can berotated by hand in order to adjust the shutter between open and closedpositions. A stop 41 on the end 35 of the hinge may be employed to limitopening movement of the shutter to the position shown in Figure 2.

Similarly, there is provided a box 45 beneath the inlet opening 34constructed in substantially the same fashion as the box 25 and equippedwith a comparable shutter operating in the same fashion by manipulationof a button 40'. In this instance a tube 46 extending outwardly from thebox 45 is illustrated as being rectangular in cross-sectional shapeprovided with an upper wall 47, a lower wall 48 and side walls 49 and50. The tube .46 similarly extends in a somewhat oblique direction sothat an opening 51, thereof, is directed away from the pick-up 18, buton a side of the chamber 17 opposite from the opening 29. In the tube46, a different type of filtering device is employed embodied in a setof bafiles 52, 53 and 54 which may be of Wood or an ap propriate plasticmaterial. The battles are mounted in the tube in such fashion that they'provide openings 55, 56 and 57 on alternately opposite sides of the tube46. Constructed in this fashion and of appropriate filter material assuggested, the major portion of pick tones which find their way into thebox 45 are filtered out as the sound travels back and forth from oneside to the other of the tube 46 before it emerges from the opening 51.Those portions of pick tones which emerge are modified efiectivelybefore they finally reach the pick-up and the resulting amplified effectis consequently of a greatly improved character.

Outlet openings 58 and 59 are provided in the upper wall 15 adjacent thepick-up 18 and at a location removed from the inlet openings 23 and 24.This permits the filtered sound to escape from the chamber 17 and avoida muffled efiect which would otherwise occur.

In operation of the device the instrument is played in the usual fashionby fingering the strings 9 to pro duce tones of dilferent pitch, thestrings being struck with a customary pick or plectrum. When theinstrument is to sound both acoustically and electronically, theshutters are adjusted so that the inlet openings 23 and 24 are open. Theelectronic system is turned, on by use of the switch 22 and the soundstravel in several directions. Some sounds pass through the tubes 28 and46, thence outwardly from the openings at the ends of the tubes and intothe chamber 17. There the properly filtered sounds and tones are pickedup by' the pick-up 18 to be passed through the amplification system andsubsequently through a loudspeaker (not shown). Sounds also are emittedthrough the openings 58 and 59. A portion of the sound, however, whenreflected by the bottoms of the boxes 25 and 45, passes outwardly fromthe openings 23 and 24.

On those occasions where the instrument is to be played onlyacoustically, it is only necessary to shut off the amplification systemby opening the switch 22 and leaving the shutters in open position.

Some selective adjustment with respect to tone quality can be achieved,however, by manipulating one or the other of the shutters 33. If trebletones are to be emphasized, the shutter for the opening 24 is closed andthe shutter for the opening 23 is open. If bass tones are to beemphasized, the shutter for the opening 24 is opened and that for theopening 23 is closed. Where both bass and treble tones are to beblended, both shutters are opened.

In either event, the filtered tones pas through the tubes and thencearound the interior of the chamber 17 wherein they are picked up by theamplification system only after filtering takes place.

There has accordingly been provided a musical instrument wherein theinitially produced sounds from the strings are filtered by a simplefiltering system before it is possible to have those tones picked upelectronically, and hence only desirable tones will be emitted from theamplification system. Therefore, even though pick tones be present, theycan be heard only close to the instrument and are insignificant in viewof the dominance of pure tones coming from the amplification system. Thefiltering system, moreover, is of simple character such that the boxesand tubes can be molded from conventional synthetic plastic materialsand fastened to the upper wall 15 without it being necessary to changethe construction of the instrument case in any fashion. It will beunderstood that in those instrument Where only one opening is providedin the upper wall, the shutter and shutter mechanism can be dispensedwith thereby making the device still simpler but without, however,impairing in any way the operation of the filtering system hereindescribed.

Although I have herein shown and described my invention in what I haveconceived to be the most practical and preferred embodiment, it is.recognized that departures may be made therefrom within the scope of myinvention, which is not to be limited to the details disclosed hereinbut is to be accorded the full scope of the claims so as to embrace anyand all equivalent structures and devices. 7

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. An electrically amplified stringed instrument comprising a casehaving wall portions forming a sound chamber, a bridge on the upper wallportion, a neck, strings extending from the neck across the upper wallportion of the case and an electronic pick-up element in the chamber,means forming an inlet opening in said upper wall portion beneath thestrings intermediate the neck and the bridge, a box within thechamber'and surrounding the under side of the inlet opening, an outlettube extending from the box into the chamber forming a sound pathbetween the box and the pickup, and sound modifying means in the tube.

2. An electrically amplified stringed instrument comprising a casehaving wall portions forming a sound chamber, a bridge on the upper wallportion, a neck, strings extending from the neck across the upper wallPQItiOn and an electronic pick-up element in the chamber, means formingan inlet opening in said upper wall portion beneath the stringsintermediate the neck and the bridge, means forming an outlet opening inthe case, a box for the inlet opening within the chamber and surroundingthe underside of the inlet opening, an outlet tube extending from thebox into the chamber, and sound modifying means in the tube.

3. An electrically amplified stringed instrument comprising a casehaving wall portions forming a sound chamber, a bridge on the upper wallportion, a neck, strings extending from the neck across the upper wallportion and an electronic pick-up element in the chamber, means formingan inlet opening in said upper wall portion beneath the stringsintermediate the neck and the bridge, means forming an outlet opening inthe case, a box for the inlet opening within the chamber and surroundingthe under side of the inlet opening, a tube extending from the box intothe chamber in a direction away from the pick-up, and a plurality ofspaced sound modifying elements in the tube.

4. An electrically amplified acoustical stringed instrument comprising acase, side, bottom and upper wall portions forming a sound chamber, abridge on the upper wall portion, a neck, strings extending from theneck across the upper wall portion and an electronic pick-up element inthe chamber adjacent the end remote from said neck, means forming aplurality of inlet openings in said upper wall portion beneath thestrings intermediate the neck and the bridge, and means forming anoutlet opening, a box for each inlet opening within the chamber andsurrounding the under side of each respective inlet opening, an outlettube extending from each box in a generally oblique direction relativeto the strings and discharging into the chamber in a direction away fromthe pick-up, and a plurality of spaced sound modifying baflles extendingtransversely in each tube, a shutter for each inlet opening hinged tothe case at one side thereof having one position closing the respectiveinlet opening and another position lowered into the box leaving saidinlet opening clear, and a control attached to each said shutter andlocated on the case enabling optional opening and closing of said inletopenings.

References Cited in the file of this patent UNITED STATES PATENTS

